Drinking Water: A Groundwater Modeling Study in Newmarket, NH CAW - PowerPoint PPT Presentation

Sea-Level Rise Impacts on Drinking Water: A Groundwater Modeling Study in Newmarket, NH CAW Workshop April 26, 2018 5:00pm Hugh Gregg Coastal Conservation Center

Research – “investigation or experimentation aimed at the discovery and interpretation of facts, revision of accepted theories or laws in the light of new facts, or practical application of such new or revised theories or laws” Planning – “the act or process of making or carrying out plans” 2

Introduction Existing model… …different application 3

Groundwater Rise with Sea-Level Rise Scenarios 4

Project Goals  Increase the understanding of how sea-level rise may impact groundwater sources of drinking water  Identify areas of T own that may be vulnerable to groundwater rise due to sea-level rise  Provide the T own with suggested adaptation strategies to assist in becoming more resilient 5

Process Data Collection May-June T echnical Planning Committee Meeting #1 – 2016 Model Construction June-Oct 6/23/16 Model Scenarios Nov-Jan T echnical Planning Committee Meeting #2 – Analysis & Mapping Jan-Mar 3/9/17 2017 Final Report & Mar-May T echnical Planning Recommendations Committee Meeting #3 – Final Presentation June 5/5/17 6 6

Outcomes  Groundwater Rise  Vulnerable Infrastructure and Potential Contamination Sites  Saltwater Intrusion  Septic System Environmental Impacts 7

Groundwater Rise Highlights  Ranges from 1 to 7ft to occur within 0.8 miles of the coast  Moody Point is projected to experience the most rise 8

Vulnerable Infrastructure and Potential Contamination Sites  Moody Point (3 wells)  Two potential contamination sites  One sewer pump station (M. Point)  30 private drinking water wells 9

Saltwater Intrusion Moody Point already  experiences high total dissolved salt (TDS) levels The two deeper wells are  experiencing higher salt concentrations Closer to groundwater  table are more susceptible to intrusion Model predicts an 8-12%  increase in salinity concentrations 10

Septic System Environmental Impacts Limitations for septic tank  leach fields Wetlands, floodplains, and  100ft buffer around surface waters Determine where septic tanks  and leach fields are more vulnerable to groundwater rise Can be used as a preliminary  guide (additional information is needed) 11

Recommendations  Six planning topics: Outreach and Infrastructure & 1. 4. Engagement equipment Planning/Regulatory Additional research 2. 5. Long-term drinking water Emergency management 3. 6.  Adaptation strategies, timeframe, and potential partners/programs and additional needs 12

Accomplishments & Next Steps  Data was included in the 2018 multi-hazard mitigation plan update  Newmarket is considering expanding municipal water infrastructure to Moody Point development  Durham, in partnership with SRPC will be seeking funding to do a similar analysis 13

Thank You! Kyle Pimental, Principal Regional Planner Strafford Regional Planning Commission 150 Wakefield Street, Suite 12 Rochester, NH 03867 603.994.3500 kpimental@strafford.org www.strafford.org 14